Test device



H R. MENEFEE TEST DEVICE Dec. 16, 1924.

Filed Deo. 1920 MME.-

lifi

Patented Dec. 16, 1924.

UNTED STATES PATENT QFFICE.

HARRY R. MENEFEE, F GLEN B-IDGE. NET JERSEY, ASSGNOR TO VJESTER'N ELEC- TEST BEVIGE.

Application led December To all w /Lom t may conce/w Be it known that l, HARRY R. MnNnrnn, a citizen of the United States, residing at Glen Ridge, in the county ol Essex, State of New Jersey, have invented certain new and uset'ul improvements in Test Devices, oi' which the following .is a full, clear, concise, and exact description.

rlhis invention relates in general to test devices, and more particularly to that type ot test device generally ret'erred to as serv- .ice observing plugs.

It is customary to provide in the terminal room of a telephone exchange a connecting device, carried on the end otl a flexible conducting cord, for temporarily connecting said oord to an exposed part of the line, the other end ot the ccrd being connected, for example, to a service observing operators desk. By the provision otl such a device, the service on a line may be tested by temporarily connecting the operators equipment to the desired line.

lt is one object of the invention to pro vide a testing device, simple in construction, reliable in operation, and which can ybe easily and quickly adjusted for use.

In accordance with the present invention there is provided la. test plug in which a plurality of spring-pressed plunger contacts are adapted to engageV a front strip, and a plunger actuated by a positive locking cam is adapted to engage the back strip, of the usual terminal block, thus holding the plug in position for use.

The invention will be better understood from a, consideration o'l' the following description taken in combination with the accompanying drawing and the appended claims.

Fig. l is a view in perspective showing a test device embodying the features of the present invention attached to the strips of a terminal block; and Fig. 2 is a detail view showing the enclosed spring-pressed contacts, and the method ot connecting the flexible conducting cords thereto, certain parts being broken away lor the sake of clearness.

Referring first to Fig. l, the test clamp comprises a frame or plate 1 carrying on one end a plate or jaw 2, mounting la plurality of spring pressed plunger contacts and enclosed in a micarta shell l. On the other end is mounted a plate or jaw 6, 1920. Serial No. 428,545.

carrying lthe plunger 6 and the cam 7 adapted to rock on a pin 8 :as a bearing, and held in engagement with the plunger 3 by means oli the spring 9. Plunger (S is adapted to slide in a slot At'ormcd in the plate or jaw 5 and is {irmly held in any desired position in the said slot by means ot the pressure exerted lby the positive lock ing cam or dog T. Thusl` the plunger 6 may readily be pressed torwiard to engage any under strip l0 of the terminal block 1 l, but is held by means of the cam 7 against any pressure tending to release the plug from its hold on the said terminal strips. Upon applying pressure to the cam 7 however, the said cam releases its grip on the plunger (i, and the cliamp may be readily removed irom operative engagement with the terminal strips 10.

its is shown in Fig. 2, the cont-acts 3 are mounted on the plate 2 and are suitably insulated therefrom by means of insulating strips l2. Each contact plunger 3 is provided with a. spring 13 by means of which the said contacts are held securely in engage icnt with the ends of the corresponding terminal strips 10. Flexible conducting cords are. adjusted to corresponding binding screws 14 before the plug is assembled. The micarta casing 4 is readily removable and is provided as a protection to the spring pressed contacts 3.

t feature oit the invention is the ease with which the plug may be adjusted to an operable position. The contacts 3 are placed in engagement with the Jt'our terminal strips to which the tip, ring, relay and line lamp conductors, respectively of a given line are usually connected. The plunger 6 is simply pressed into engagement with the opposite end o'l' any ol these terminal strips and the plug is in a position for use. Upon pressing the cam 7 lightly with the linger, the plunger 5 releases its hold upon the terminal strip l0, and the clamp may be disengaged.

As a plug constructed in accordance with this invention does not depend upon the terminal support l1 as means for holding it in position, it is apparent that there is no tendency to weaken the supporting structure by constant hard usage.

That is claimed is:

l. A test clamp comprising a trame, a plurality ot spring-pressed plunger contacts adapted to engage a front strip of a terminal block, an adjustable plunger slidably mounted in said iframe and adapted to engage a back strip of a terminal block, and a positive lool-ing cani cooperating with said plunger to loek it in au)v set position holding the clamp in place on the terminal block.

2. A test clamp Comprising a substantially C-sliaped frame, a pluralityv of springpressed contacts mounted in one arm of said frame, and adapted to engage a front strip of a 4tern'iiinil blockr` a plunger slidablv mounted in the opposite arm or' said frame and adapted to engage a back strip of the terminal block, a spring member disposed within said trame.y and a Cam held by said spring in engagement with said plunger to control the movement thereof.

3. A test clamp comprising a frame, a block oji' insulating material arranged therein, Contacts movable in said block, a bar slidably arranged in said frame and disposed in line eoaxially with respectto one of said contacts, and an automatically operated grip member for positively securing said bar in adjusted position with reference to said contacts.

fl. A test clamp comprising a frame, a removable block of insulating material seeureliv arranged in said frame, sprin pressed contacts slidably arranged in saifgi block, an adjustable member movable longitudinally in a plane common to the direction of movement ot said contacts, and automatic means for restraining the movement oi said member against the action of said spring pressed contacts.

In witness whereof, I hereunto subscribe my naine this 30th day of November A. D., 1920.

HARRY R. MENEFEE. 

